Facing the league’s best side on their turf was always going to be a tough ask for Ryan’s men, especially given Leinster have won the last three titles.
And so it proved as the Irish side won with a bonus point thanks to five converted tries from Garry Ringrose, Jordan Larmour, James Lowe (2) and Ryan Baird.
Dragons got one back through Ashton Hewitt, but their line-out was poor as Ryan admitted.
“I don’t think I’ve come here very often and been disappointed we missed an opportunity,” he said.
“We had four or five line-outs on the five-metre line and came away with nothing which is credit to Leinster, but that’s exactly where we need to be better.
“If you stay in a really physical game and make it difficult for Leinster to take their chances, you have to take your own. That’s the lesson that will come out of today.
“There will be lots of positive messages, but we have to be critical of ourselves. We’ve been pretty open and honest about it in the changing room.”
Ryan then added: “I don’t think it’s just the line-out. It’s about coping under pressure. That’s what we want to do and we have to be better.”
Dragons had their moments and never stopped fighting, but they also never looked like winning as they struggled with Leinster’s brutish physicality and speed of ball.
They also weren’t helped by a first-half yellow card for centre Jamie Roberts on his PRO14 debut for a high tackle.
Ringrose, Larmour and Lowe sent Dragons to the break 21-0 down with conversions coming from Johnny Sexton, Ringrose and Ross Byrne.
Lowe and Baird added further scores after the break with the latter coming from another wonky Dragons line-out.
“I love their effort and the fact they threw everything physically into the game as that was right out of our comfort zone. There is no doubting that,” Ryan added.
“I’m always proud of them and I don’t set any targets about where they should be. Of course we want to be better and if we’re going to do that the players have to solve some things themselves.”
The one bright moment for the Dragons was wing Hewitt’s outrageous, acrobatic finish in the corner despite him under pressure from the covering Josh van der Flier.
“I think it was exactly what we were expecting. It was a level up in terms of pace, especially after the yellow card,” Ryan said.
“There were some things we’ll need to look at and the physicality was enormous, but I thought we got to grips with things in the second half and we’ll come away from this disappointed with ourselves.
“If we want to test ourselves at this level we have to be better.”
